Arthur bollermann



(No Model.)

' A. BOLLERMANN.

PIANO STRINGING DEVICE.

No. 493,748. Patented Mar. 21,1898.

UNITED STATES PATENT OFFICE.

ARTHUR BOLLERMANN, OF NEW YORK, N. Y.

PIANO-STRINGING DEVICE.

SPECIFICATION forming part of Letters Patent No. 493,748, dated March21, 1893.

' Application filed November 14, 1892. Serial No. 451,878. (No model.)

To all whom it may concern:

Be it known that LARTHUR BOLLERMANN, of the city, county, and State ofNew York, have invented a new and useful Improvement in Piano-StringingDevices; and I do hereby declare that the following is a full and exactdescription thereof, reference being, had to the accompanying drawings,and to the letters of reference marked thereon, making a part of thisspecification.

The object of myinvention is to provide an improved agraffe andbridge-bearing for the strings of pianos which shall be inexpensive andeasily applied, shall entirely prevent torsional strain on thesounding-board, shall f urnish a metallic bearing 'for the strings, andshall permit all of the strings of a given note to be of equal lengthbetween the bridge and the hitch -pin plank and the wrest -plank,thereby greatly improving the purity of the tone.

In the drawings: Figure l is a longitudinal section through thesounding-board of the piano showing a string stretched on the same. Fig.2 is an outline plan view of the soundingboard of a piano indicating inthe general Way the application of my improvement. Fig. 3 is a detailplan view of a construction shown in Fig. 1, but; on a larger scale.Fig. 4 is a section on the line 0c-0c of Fig. 3. Fig. 5 is a detail viewin longitudinal section of my improvement. Fig.6 is a section on theline y-y of Fig. 5.

The strings a are stretched as shown from the hitch-pins b in the plankB to the wrestpins 0 in the wrest-plank O, and between the two pointslie over the bridge D. Usually the strings lie directly upon the uppersur face of the bridge and as the latter is curved the strings lieacross it at different angles with the result that the two or threestrings of a single note are of different lengths. Furthermore thequality of the tone is impaired by the fact that the strings do notrest, as they should, upon a point only. Accordingly I provide for thestrings of each single set or note an independent metal under-layer Ehaving two flanges e, e, upon which the strings rest rather than uponthe bridge itself. As each under-layer is entirely independent of everyother under-layer of the bridge it may be so placed in every case, asindicated in Fig. 2, that its flanges are at right angles to the line ofthe strings crossing it.

The strings are slightly depressed between the flanges e, e, and areheld firmly in contact with them by an independent bearer for eachunder-layer. As shown in Figs. 1, 2, 3 and 4 the bearer consists of ahalfround bar F which is held in place by two screws f which passbetween the strings and through holes 6 in the under-layer into thebridge D. I prefer, however, the form of bearer which is shown in Figs.5 and 6 because of its greater simplicity and ease in application. Inthis case the bearer is composed of a bar or plate G having a centralaperture g and two lateral notches g',g', and a single centrallydisposed screw-threaded shank g lVith the bearer shown in Figs. 3 and tthe two screws and their holes are necessary and the strings must be putin place before the bearer plate, but with the form shown in Figs. 5 and6 the bearer is put in place first and the strings stretchedsubsequently, one being passed through the central aperture g and theothers slipped into the lateral notches g. In either case the screwwhich holds the bearer also keeps the under-layer in place.

It is evident that as the string rests at two points upon the bridgewith the bearer between there can be no torsional strain of anydescription upon the bridge. Furthermore, as every string crosses theflanges of the under-layer at a right angle therewith it rests as nearlyas may be upon a single point and buzzing of the string is therebyentirely prevented.

I am aware that it has been proposed to carve the top of the bridge toform a series of ridges at right angles to the strings, but the carvingof the bridge is in the end more eX- pensive than my under-layer and thestrings will moreover quickly out into the wood to the injury of thetone.

I claim as my invention- 1. In a piano, the combination with thesounding-board, the bridge, and the strings, of an independent, metallicunder-layer for each string or set of strings, and a cooperatingindependent bearer composed of a bar or plate having a centralperforation, two lateral notches, and a screw-threaded shank to pass Intestimony whereof I have signed my through the under-layer into thebridge, subname to this specification in the presence of 10 stantiallyas shown and described. two subscribing witnesses.

2. Abearer for piano strings composed of a plate or bar having a centralperforation and ARTHUR BOLLERMANN' two lateral notches, and a centrallydisposed WVitne'sses: screw-threaded shank, substantially as shown A. N.J ESBERA, and described. A. \VIDDER.

